Solo Sabotage.

If there is a lack of minions or spells which will cause games to last too long, have it as a battle royale. Something like 5-6 different players linked together and the sabotage consumables goes to all opponents. For players who lose all their rift points, let them use a special stash of consumables which consist of Bosses, Mercenaries and many of those disgusting spells... this way, they can help end the game faster, while giving those alive some intense actions to become the sole survivor.